Quadrupedal siblings in Turkey challenge evolutionary theories

Despite our scientific advancements, many mysteries remain unsolved. One such enigma was explored in the 2006 BBC documentary "The Family That Walks On All Fours," which tells the story of a family in a remote Turkish village where five siblings have always walked on their hands and feet. The cause of this unusual, ape-like walking has sparked significant scientific debate.

One UK expert speculated that quadrupedal walking might be an evolutionary throwback, suggesting this family could offer insights into how our ancestors transitioned from four-legged to two-legged locomotion. Meanwhile, a team of German scientists proposed that a genetic abnormality was responsible, locating a gene on chromosome 17 that they believed was crucial for bipedalism but possibly deficient in these siblings.

However, professor and neuropsychologist Nicholas Humphrey from the London School of Economics, UK, disproved this theory. The professor explained that humans must have undergone a complex evolutionary process to walk on two feet, which involved several alterations to our genes and skeletal structure. He noted that not all siblings walked exclusively on four feet. Some altered between bipedal and quadrupedal walking.

Humphry took the family for an MRI scan, and the results showed the presence of cerebellar ataxia, a condition that affects balance and coordination. However, experts knew that this wasn't the primary cause of the siblings' quadrupedalism and came up with other possibilities. Despite surface-level similarities to how chimpanzees and gorillas walk, Humphrey noted significant differences. While apes walked on their knuckles, the siblings pressed their palms on the ground while keeping their fingers up. "I think it's possible that what we are seeing in this family is something that does correspond to a time when we didn't walk like chimpanzees but was an important step between coming down from the trees and becoming fully bipedal," Humphrey explained.

The neuropsychologist believed that the siblings walking on all fours was not because of a strange evolution but was instead due to a brain abnormality that they carried. Humphry suggested that the family's quadrupedalism was nothing but the result of a lack of health service in the village, as per a documentary by 60 Minutes Australia. When the children started walking on all fours as babies, no one was there to guide the family to teach the little ones to walk on two feet.

Humphrey was astonished that no one intervened to help the children, even after so many years. Humphrey and a team of experts provided the siblings with a walking frame, and the results were astonishing. It took just a few hours for the siblings to walk upright, and they were delighted. The team returned to the Turkish village a while later to check on the siblings' progress and surprisingly, they were all embracing bipedalism. 

Editor's note: This article was originally published on April 24, 2024. It has since been updated.